Model of EBV in peripheral blood lymphocytes. Lymphocytes infected by EBV are suggested to exist in three different states. In veiled latency, the immunodominant EBNA's are not expressed, the C promoter is methylated and its silence enforced. In exposed latency, the immunodominant EBNA's are expressed and the C promoter is not methylated. In lytic infection, it is proposed that the C promoter is not methylated.